Family Leave Insurance Act of 2008

Family Leave Insurance Act of 2008 - Directs the Secretary of Labor to establish a Family and Medical Insurance Program, mandatory for certain covered employers.

Authorizes the Secretary to: (1) contract for a state to provide specified leave benefits in that state through the Program, including expansion of a pre-existing state program; or (2) at a governor's request enter an interagency agreement with the Commissioner of the Social Security Administration to establish and provide Program benefits directly through a state Family and Medical Insurance Program.

Entitles eligible employees to Program benefits that include specified percentages of their daily earnings for 12 workweeks of leave under the Family and Medical Leave Act of 1993 during any 12-month period.

Authorizes any employer, with the Secretary's approval, to establish a voluntary plan meeting specified criteria.

Specifies prohibited acts by an employer, and penalties for violations.

Requires the Director of the Office of Personnel Management (OPM) to establish a Civil Service Family and Medical Leave Insurance Program with the same Program benefits for certain federal agency employees.

Establishes the Family and Medical Leave Insurance Fund in the Treasury.

Amends the Internal Revenue Code to impose a family and medical leave premium on every individual and every employer to finance a Family and Medical Leave Trust Fund in the Treasury for Program benefits. Exempts from such premium: (1) employers or self-employers with voluntary plans approved by the Secretary as equivalent or better than the Program; and (2) small employers who have elected not to participate in it.